Serial voting, yes. Just voting, no. That's right, StackExchange has methods of preventing voting, and it sucks. It punishes you for downvoting. Poor questions and answers should be downvoted, and we should not punish that. If we're going to have a method of preventing serial voting, we should just prevent new users from voting if they don't have a certain amount of points (maybe a higher amount for downvoting?), so people can't just create accounts to upvote themselves, and can't downvote unless other people proved this user is good. The user could start serial voting later, though, which is really not preventable.